Preparing for a trip to Ireland, I carefully studied this forum and the many good ideas people offered. Based on thoughtful recommendations, I finally ordered a pair of Allbirds Wool Runners - and I'm glad I did. However I made one mistake that could have been avoided. I assumed my shoe size based on shoes I've worn for several years. Don't do that!
On receiving these shoes from the sheep in New Zealand, I discovered that the left shoe was a bit snug (though the right shoe is a perfect fit). It turns out my left foot is more than a half size larger than my right foot - and this is apparently not uncommon. The solution was to have my feet measured by a local shoe store and in the end I opted for a high quality pair of running shoes with a size slightly larger than my right foot. The Allbirds served as backup shoes.
I'll be getting my feet measured before the next trip, that's for sure!